Various pasty comestibles, especially dairy products, are marketed in cup-shaped portions or packages of predetermined volume or weight on a large scale so that machines for portioning and packaging such pasty materials are required.
Such machines can be used for the portioning of butter, margarine, cheeses and like substances which can be produced in a pasty form and which are to be distributed in packaged portions.
The term "packaged" is here intended to refer to any enclosure for the comestible substance and can be a foil, sheet or laminate layer which forms a one-piece or multi-part enclosure.
A one-piece enclosure, for example, may wrap the portion in a foil of metal (aluminum foil) or a synthetic resin material or even a cellulosic (such as paper) layer. Multi-part packages may include a cup of a somewhat stiffer material to which a cover may be applied. Multi-part packages also can include multi-layer foils which are sealed together.
Earlier machines for the portioning and packaging of pasty materials, especially butter, margarine and the like, have comprised a feed tube around which the filling head and, synchronously with the latter, a carrier for the packaging to be filled, were rotated. The filling head or a member thereof was lowered into the packaging, e.g., in the form of a vertically displaceable filling tube and the up-and-down movement of the latter was controlled by a cam arrangement.
This movement deposited a predetermined portion of the pasty material in the packaging at a predetermined station along the path of the latter and the packaged portion was thereafter removed at a subsequent station.
An apparatus for this purpose and of this type was described, for example, in British Pat. No. 1,079,526 and served for the packaging of molten cheese.
In this device, an extension of a supply vessel for the pasty material was surrounded by a metering head rotatable about a vertical axis and carrying an axially shiftable cam-controlled filling tube provided on its lower end with a nozzle insertable in a preformed package coupled with the metering head by a chain.
The tube was formed with a piston, also operated by cam means, with the movements of cylinder and piston so controlled that a predetermined portion of the product was introduced into the package and was forced out of the tube in a lowered position of the latter.
To prevent undesired passage of the material out of the filling tube, special slide valves were provided above the nozzle, also under cam control.
This machine was extremely complex, difficult to regulate and adjust and unreliable, especially with respect to the timing of the filling process. Difficulties were encountered in efforts to coordinate this machine with the machines for forming the package. Obviously this system was not operative at all in the case in which the package was not preformed.
It is also known to provide metering and packaging devices (see U.S. Pat. No. 4,060,109) in which the metering is effected by cam-controlld pistons in filling tubes.
I am not aware, however, that any of these earlier systems have been fully effective when simultaneous portioning and packaging of the pasty products was required.